1 // SPDX-License-Identifier: GPL-2.0-only 2 /* Abilis Systems MODULE DESCRIPTION 3 * 4 * Copyright (C) Abilis Systems 2013 5 * 6 * Authors: Sascha Leuenberger <sascha.leuenberger@abilis.com> 7 * Christian Ruppert <christian.ruppert@abilis.com> 8 */ 9 10 #include <linux/kernel.h> 11 #include <linux/module.h> 12 #include <linux/platform_device.h> 13 #include <linux/gpio/driver.h> 14 #include <linux/slab.h> 15 #include <linux/irq.h> 16 #include <linux/irqdomain.h> 17 #include <linux/interrupt.h> 18 #include <linux/io.h> 19 #include <linux/of.h> 20 #include <linux/of_platform.h> 21 #include <linux/spinlock.h> 22 #include <linux/bitops.h> 23 #include <linux/pinctrl/consumer.h> 24 25 #define TB10X_GPIO_DIR_IN (0x00000000) 26 #define TB10X_GPIO_DIR_OUT (0x00000001) 27 #define OFFSET_TO_REG_DDR (0x00) 28 #define OFFSET_TO_REG_DATA (0x04) 29 #define OFFSET_TO_REG_INT_EN (0x08) 30 #define OFFSET_TO_REG_CHANGE (0x0C) 31 #define OFFSET_TO_REG_WRMASK (0x10) 32 #define OFFSET_TO_REG_INT_TYPE (0x14) 33 34 35 /** 36 * @base: register base address 37 * @domain: IRQ domain of GPIO generated interrupts managed by this controller 38 * @irq: Interrupt line of parent interrupt controller 39 * @gc: gpio_chip structure associated to this GPIO controller 40 */ 41 struct tb10x_gpio { 42 void __iomem *base; 43 struct irq_domain *domain; 44 int irq; 45 struct gpio_chip gc; 46 }; 47 48 static inline u32 tb10x_reg_read(struct tb10x_gpio *gpio, unsigned int offs) 49 { 50 return ioread32(gpio->base + offs); 51 } 52 53 static inline void tb10x_reg_write(struct tb10x_gpio *gpio, unsigned int offs, 54 u32 val) 55 { 56 iowrite32(val, gpio->base + offs); 57 } 58 59 static inline void tb10x_set_bits(struct tb10x_gpio *gpio, unsigned int offs, 60 u32 mask, u32 val) 61 { 62 u32 r; 63 unsigned long flags; 64 65 spin_lock_irqsave(&gpio->gc.bgpio_lock, flags); 66 67 r = tb10x_reg_read(gpio, offs); 68 r = (r & ~mask) | (val & mask); 69 70 tb10x_reg_write(gpio, offs, r); 71 72 spin_unlock_irqrestore(&gpio->gc.bgpio_lock, flags); 73 } 74 75 static int tb10x_gpio_to_irq(struct gpio_chip *chip, unsigned offset) 76 { 77 struct tb10x_gpio *tb10x_gpio = gpiochip_get_data(chip); 78 79 return irq_create_mapping(tb10x_gpio->domain, offset); 80 } 81 82 static int tb10x_gpio_irq_set_type(struct irq_data *data, unsigned int type) 83 { 84 if ((type & IRQF_TRIGGER_MASK) != IRQ_TYPE_EDGE_BOTH) { 85 pr_err("Only (both) edge triggered interrupts supported.\n"); 86 return -EINVAL; 87 } 88 89 irqd_set_trigger_type(data, type); 90 91 return IRQ_SET_MASK_OK; 92 } 93 94 static irqreturn_t tb10x_gpio_irq_cascade(int irq, void *data) 95 { 96 struct tb10x_gpio *tb10x_gpio = data; 97 u32 r = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_CHANGE); 98 u32 m = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_INT_EN); 99 const unsigned long bits = r & m; 100 int i; 101 102 for_each_set_bit(i, &bits, 32) 103 generic_handle_irq(irq_find_mapping(tb10x_gpio->domain, i)); 104 105 return IRQ_HANDLED; 106 } 107 108 static int tb10x_gpio_probe(struct platform_device *pdev) 109 { 110 struct tb10x_gpio *tb10x_gpio; 111 struct device *dev = &pdev->dev; 112 struct device_node *np = dev->of_node; 113 int ret = -EBUSY; 114 u32 ngpio; 115 116 if (!np) 117 return -EINVAL; 118 119 if (of_property_read_u32(np, "abilis,ngpio", &ngpio)) 120 return -EINVAL; 121 122 tb10x_gpio = devm_kzalloc(dev, sizeof(*tb10x_gpio), GFP_KERNEL); 123 if (tb10x_gpio == NULL) 124 return -ENOMEM; 125 126 tb10x_gpio->base = devm_platform_ioremap_resource(pdev, 0); 127 if (IS_ERR(tb10x_gpio->base)) 128 return PTR_ERR(tb10x_gpio->base); 129 130 tb10x_gpio->gc.label = 131 devm_kasprintf(dev, GFP_KERNEL, "%pOF", pdev->dev.of_node); 132 if (!tb10x_gpio->gc.label) 133 return -ENOMEM; 134 135 /* 136 * Initialize generic GPIO with one single register for reading and setting 137 * the lines, no special set or clear registers and a data direction register 138 * wher 1 means "output". 139 */ 140 ret = bgpio_init(&tb10x_gpio->gc, dev, 4, 141 tb10x_gpio->base + OFFSET_TO_REG_DATA, 142 NULL, 143 NULL, 144 tb10x_gpio->base + OFFSET_TO_REG_DDR, 145 NULL, 146 0); 147 if (ret) { 148 dev_err(dev, "unable to init generic GPIO\n"); 149 return ret; 150 } 151 tb10x_gpio->gc.base = -1; 152 tb10x_gpio->gc.parent = dev; 153 tb10x_gpio->gc.owner = THIS_MODULE; 154 /* 155 * ngpio is set by bgpio_init() but we override it, this .request() 156 * callback also overrides the one set up by generic GPIO. 157 */ 158 tb10x_gpio->gc.ngpio = ngpio; 159 tb10x_gpio->gc.request = gpiochip_generic_request; 160 tb10x_gpio->gc.free = gpiochip_generic_free; 161 162 ret = devm_gpiochip_add_data(dev, &tb10x_gpio->gc, tb10x_gpio); 163 if (ret < 0) { 164 dev_err(dev, "Could not add gpiochip.\n"); 165 return ret; 166 } 167 168 platform_set_drvdata(pdev, tb10x_gpio); 169 170 if (of_find_property(np, "interrupt-controller", NULL)) { 171 struct irq_chip_generic *gc; 172 173 ret = platform_get_irq(pdev, 0); 174 if (ret < 0) 175 return ret; 176 177 tb10x_gpio->gc.to_irq = tb10x_gpio_to_irq; 178 tb10x_gpio->irq = ret; 179 180 ret = devm_request_irq(dev, ret, tb10x_gpio_irq_cascade, 181 IRQF_TRIGGER_NONE | IRQF_SHARED, 182 dev_name(dev), tb10x_gpio); 183 if (ret != 0) 184 return ret; 185 186 tb10x_gpio->domain = irq_domain_add_linear(np, 187 tb10x_gpio->gc.ngpio, 188 &irq_generic_chip_ops, NULL); 189 if (!tb10x_gpio->domain) { 190 return -ENOMEM; 191 } 192 193 ret = irq_alloc_domain_generic_chips(tb10x_gpio->domain, 194 tb10x_gpio->gc.ngpio, 1, tb10x_gpio->gc.label, 195 handle_edge_irq, IRQ_NOREQUEST, IRQ_NOPROBE, 196 IRQ_GC_INIT_MASK_CACHE); 197 if (ret) 198 return ret; 199 200 gc = tb10x_gpio->domain->gc->gc[0]; 201 gc->reg_base = tb10x_gpio->base; 202 gc->chip_types[0].type = IRQ_TYPE_EDGE_BOTH; 203 gc->chip_types[0].chip.irq_ack = irq_gc_ack_set_bit; 204 gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit; 205 gc->chip_types[0].chip.irq_unmask = irq_gc_mask_set_bit; 206 gc->chip_types[0].chip.irq_set_type = tb10x_gpio_irq_set_type; 207 gc->chip_types[0].regs.ack = OFFSET_TO_REG_CHANGE; 208 gc->chip_types[0].regs.mask = OFFSET_TO_REG_INT_EN; 209 } 210 211 return 0; 212 } 213 214 static int tb10x_gpio_remove(struct platform_device *pdev) 215 { 216 struct tb10x_gpio *tb10x_gpio = platform_get_drvdata(pdev); 217 218 if (tb10x_gpio->gc.to_irq) { 219 irq_remove_generic_chip(tb10x_gpio->domain->gc->gc[0], 220 BIT(tb10x_gpio->gc.ngpio) - 1, 0, 0); 221 kfree(tb10x_gpio->domain->gc); 222 irq_domain_remove(tb10x_gpio->domain); 223 } 224 225 return 0; 226 } 227 228 static const struct of_device_id tb10x_gpio_dt_ids[] = { 229 { .compatible = "abilis,tb10x-gpio" }, 230 { } 231 }; 232 MODULE_DEVICE_TABLE(of, tb10x_gpio_dt_ids); 233 234 static struct platform_driver tb10x_gpio_driver = { 235 .probe = tb10x_gpio_probe, 236 .remove = tb10x_gpio_remove, 237 .driver = { 238 .name = "tb10x-gpio", 239 .of_match_table = tb10x_gpio_dt_ids, 240 } 241 }; 242 243 module_platform_driver(tb10x_gpio_driver); 244 MODULE_LICENSE("GPL"); 245 MODULE_DESCRIPTION("tb10x gpio."); 246